Two coherent sources of intensity ratio $$\alpha$$ interfere. The value of $$\frac{I_{max} - I_{min}}{I_{max} + I_{min}}$$ is:

A

$$\sqrt[2]{\frac{\alpha}{1 + \alpha}}$$

B

$$\frac{2 \sqrt{\alpha}}{1 + \alpha}$$

C

$$\frac{1 + \alpha}{2 \sqrt{\alpha}}$$

D

$$\frac{1 - \alpha}{1 + \alpha}$$